Heatwave Climate Variability of Historical CMIP5 and CMIP6 Protocols for Turkey

Heatwaves occur due to atmospheric blockages and high-pressure systems' long-term stasis in the relevant regions. They are extreme weather events that negatively affect life. For example, in Turkey, wildfires during summer 2021 succeeded in a significant heatwave event. Depending on climate change, it is expected that the intensity, duration, and frequency of heatwaves will increase. It is expected that the semi-arid zones, including Turkey, will be more affected by this change. Therefore, this study aims to analyze how well different climate models capture historical heatwave events and determine the differences depending on the CMIP5 and CMIP6 protocols. Scenarios corresponding to 4.5 W/m2 and 8.5 W/m2 radiative forcings are discussed for both protocols. The climate models (CMCC-CM and CMCC-CM2-HR4; MRI-ESM1 and MRI-ESM2-0; and HadGEM2-ES and HadGEM3-GC31-LL) which have not been studied for Turkey until now are selected to create a model ensemble for historical heatwave events. Historical heatwaves, which occurred between 1965 and 2015, were compared with the climate models, including the CMIP5 and CMIP6 protocols, using probability density functions for ten-year periods. In addition, warm spell days index (ECAHWFI), heatwave duration index (ECAHWDI), heating degree days (ECAHD) climate indices were also analyzed. Preliminary results show that the intensity, duration, and frequency of heatwaves have increased dramatically in Turkey since 2002, and the success of historical climate models in capturing these changes varies from model to model.